PLATE XVIII. 



Page. 



GOULDIA CONRADi Whitfield ^^ 



Fig. 1. Exterior of a left valve, enlarged three diameters. 



2. Interior of same. 



3. Interior of a right valve, enlarged to the same extent. 



GoULDiA DECEMNARIA Conrad ^^ 



Fig. 4. View of the type specimen, greatly enlarged. 

 Vetocardia crenulirata Conrad ^*^ 



Fig. 5. Eolarged exterior view of one of the types. 



6. Interior view of same. 



7. Enlarged view of the hinge of a left valve. 



Scambula perplana Conrad in 1^ 



Fig. 8. Exterior of one of the types. 



9. Enlarged view of a right valve (two diameters). 



10. Similar view of a left valve. 



GouLDiA DECLivis Conrad - ^^ 



Fig. 11. An enlarged copy of Mr. Conrad's figure of this shell. 



GouLDiA PARALis Conrad 1*^ 



Fig. 12. Copy of Mr. Conrad's figure cited under the description. 



13. View of a fragment of what is supposed to be the shell, as obtained by a gutta- 

 percha impression from a mold in marl from Mr. Schanck's pits near Marl- 

 borough, N. J. 



Crassatella SUBPLANA Conrad ,- 1^1 



Fig. 14. Exterior of an imperfect specimen, which shows the general form and surface 

 markings. 



15. Interior of another specimen. 



16. An imperfect cast of the species. 



DosiNiA erecta Whitfield 162 



Fig. 17. Lateral view of a small specimen, preserving the shell. 



18. Lateral view of a cast which shows the depth of the inflected cardinal border. 



19. Profile view of same, showing the inflected border. 



20. Lateral view of a large specimen, imperfect at the beak, but retaining the shell in 



part. 



LuciNA Smockana Whitfield ^30 



Fiff. 21. Left view of an internal cast, showing the form and gibbosity of the valves. 

 22. Cardinal view of same. 



LuciNA cretacea Courad 1'29 



Fig. 23. View of the interior of a right valve, enlarged. 



24. The hioge still farther enlarged. 



25. Exterior of a larger shell (two diameters). 



Dicehas DACTYLOiDES Whitfield I'-^l 



Fig. 26. View of the cast described, 



27. Lateral view of the same, .showing the muscular scar. 



304 



